Various implementations power homes and businesses without needing to connect to electric utility company-provided power, i.e., they can operate off-grid. Generally the system includes solar panel racks (e.g., photovoltaic cells on sheets stabilized using ballasts, anchors, or mounting) that generate electrical power used to provide power to a building or that is stored on batteries. The system includes the solar panel racks and an enclosure to be installed at the premises and separate from the building. The enclosure includes the batteries and inverters that are electronically connected to the solar panel racks and batteries. The inverters are configured to convert direct current (DC) electricity from the solar power racks and batteries to alternating current (AC) electricity to provide power to the building via wires electrically connecting the inverters to the main panel of the building.

A multi-level inverter topology is disclosed. A power converter circuit converts a DC source at its input to provide an alternating current (AC) at its output. The power converter circuit may have a controller operably attached to multiple series connections of switches. The controller may control one or more of the multiple series connections of switches to convert a DC input to provide multi-level AC voltages with DC offset across two terminals of the power converter circuit. The multi-level AC voltages with DC offset may then be converted by use of a plurality of series connections of switches to provide a single-phase AC voltage at a first output terminal with respect to at least one of a neutral potential, an earth potential, or a terminal of the power converter circuit.

An energy optimization system for a building includes a processing circuit configured to generate a user interface including an indication of one or more economic load demand response (energy) operation parameters, one or more first participation hours, and a first load reduction amount for each of the one or more first participation hours. The processing circuit is configured to receive one or more overrides of the one or more first participation hours from the user interface, generate one or more second participation hours, a second load reduction amount for each of the one or more second participation hours, and one or more second equipment loads for the one or more pieces of building equipment based on the received one or more overrides, and operate the one or more pieces of building equipment to affect an environmental condition of the building based on the one or more second equipment loads.

A metering and control subsystem for a photovoltaic solar system is configured for metering the photovoltaic solar system using current measurement devices and individually controlling relays to selectively energize photovoltaic branch circuits. In some examples, the metering and control subsystem includes photovoltaic branch connectors, a relay matrix, current measurement devices, and a metering and relay control circuit. The metering and control circuit is configured for metering the photovoltaic solar system using current measurement data from the current measurement devices and individually controlling the relays to selectively energize each photovoltaic branch circuit.

A string inverter control method includes: in a process of performing IV curve scanning on one or more first direct current/direct current step-up circuits, controlling a change of an output voltage of one or more second direct current/direct current step-up circuits on which the IV curve scanning does not need to be performed, where a change trend of the output voltage and a change trend of an input voltage of the one or more first direct current/direct current step-up circuits on which the IV curve scanning is performed present a non-strictly monotonically increasing relationship. Therefore, for the direct current/direct current step-up circuit on which the IV curve scanning is performed, a voltage difference between two ends of the direct current/direct current step-up circuit is not always in a relatively high state, so that a ripple current on an input inductor in the direct current/direct current step-up circuit can be reduced.

Example embodiments of systems, devices, and methods are provided herein for energy systems having multiple modules arranged in cascaded fashion for storing power from one or more photovoltaic sources. Each module includes an energy source and converter circuitry that selectively couples the energy source to other modules in the system over an AC interface for generating AC power or for receiving and storing power from a charge source. Each module also includes a DC interface for receiving power from one or more photovoltaic sources. Each module can be controlled by control system to route power from the photovoltaic source to that modules energy source or to the AC interface. The energy systems can be arranged in single phase or multiphase topologies with multiple serial or interconnected arrays. The energy systems can be arranged such that each module receives power from the same single photovoltaic source, or multiple photovoltaic sources.

In order to protect an inverter from prohibited switching states, a monitor including monitoring inputs and monitoring outputs is provided. The monitoring inputs are connected to the control outputs in order to receive the switching patterns, and the monitoring outputs are connected to the power switches. The monitor is designed to compare a transition from a first switching pattern to a second switching pattern with a number of prohibited transitions and/or with a number of permitted transitions and block the second switching pattern in the event of a match with one of the prohibited transitions and/or in the event of a deviation from the number of permitted transitions and to output the second switching pattern to the power switches via the monitoring outputs in the event of a deviation from the number of prohibited transitions and/or in the event of a match with one of the permitted transitions.

The present invention relates to an optimizer, for a solar string power generation system, comprising an Injection Circuit (IC), connected to at least one string, from an array of strings of solar panels, wherein the output of said IC is connected to the DC bus of the solar inverter. The IC comprises: (i) an MPPT mechanism, for finding the MPP of the connected string; (ii) a DC/DC converter, for converting part of the power of said connected string; wherein the DC/DC converter, converts only a part of the power of the string, that is connected to the IC, when the string is impaired, for compensating for the relative voltage difference between the voltage MPP, of the impaired string, and the MPP voltage of the DC bus of the solar inverter and the array of strings.

In one implementation, a method for a solar cell array is provided, the method includes emitting a communication message from the solar cell array by reverse biasing the solar cell array so as to cause at least a portion of the solar array to emit a detectable amount of radiation corresponding to the communication message. In one embodiment a solar cell array circuit is provided including a solar string comprising a plurality of solar cells coupled together, a charge storage device coupled to a power bus, and a bidirectional boost-buck converter having a first and second pair of MOSFETs connected in series between positive and negative rails of the power bus with an inductor coupled from between the first and second paired MOSFETs to a charging output of the solar string.

To ensure safety of people needing to service a low-voltage network of an electric power distribution system, dwellings being connected to this network may include autonomous units for producing electricity, thus generating voltage and endangering the people servicing the work. Data are obtained from consumption records from the meter of each dwelling, in regular time intervals, and meteorological data are also obtained in the geographical area of these dwellings, in order to identify at least some weather conditions conducive to the production of energy by autonomous units. A model is then applied for detecting, based on the first and second data, a coincidence between periods of lower consumption measured by a meter and weather conditions conducive to electricity production by autonomous units during these periods. Therefore, information on the presence of autonomous units in the dwelling can be deduced and given to people before their servicing.